Electrochemical gas sensors are used to measure concentrations of target gases within particular locations. For example, an electrochemical gas sensor may react with a target gas at an electrode and measure a resulting current. A typical electrochemical gas sensor may include two to four electrodes in contact with an electrolyte, such as mineral acid. The electrodes may be fabricated by fixing a high surface area precious metal on to a porous hydrophobic membrane. The working electrode(s) may be exposed to both the electrolyte and the ambient air to be monitored, such as through a porous membrane. In operation, the target gas diffuses into the sensor, through the porous membrane, to the working electrode(s) where the gas is oxidized or reduced. The resulting electrochemical reaction produces an electric current that passes through an external circuit.
Typically, an electrochemical gas sensor is installed into a gas detection system. Prior to calibration, a certain amount of time is needed for a sensor to stabilize. In short, the sensing medium, such as a sensor kernel, within the sensor needs a sufficient amount of time to warm up before it is able to properly function. For example, before operating to detect gas, a sensing medium needs to be biased or powered for a certain amount of time to warm up. The warm up time may be 5 minutes to 8 hours, depending on the gas being detected. When the warm-up operation takes place in a hazardous area, the area may need to be declassified so that the gas detection system can be opened and the electrochemical gas sensor installed.
Further, if the electrochemical gas sensor is to be removed from the gas detection system and transported to another site, the electrochemical gas sensor typically needs to be warmed up again, such as through a certain amount of power being applied thereto for a certain amount of time, before the sensor may be used with respect to the gas detection system. As noted, however, the warm up time may prevent the sensor from properly functioning for a relatively long period of time.